Immunogenic compositions in particulate form and methods for producing the same

Abstract

The invention relates to the field of immunology and vaccine development, in particular to the development of vaccines based on native antigen oligomers. Provided is an immunogenic composition in particulate form, comprising oligomers of a surface exposed polypeptide of pathogenic origin or tumor origin, or antigenic part thereof, said oligomers being bound non-covalently to a particulate carrier, and a pharmaceutically acceptable diluent or excipient. Also provided is a recombinant polypeptide comprising (A) an N- or C-terminal antigenic domain, comprising at least one surface exposed polypeptide of pathogenic or tumor origin, or antigenic part thereof, the antigenic domain being fused to (B) an oligomerization domain (OMD), said oligomerization domain being fused via (C) a linker domain to (D) a peptidoglycan binding domain (PBD) consisting of a single copy of a LysM domain capable of mediating the non-covalent attachment of the polypeptide to a non-viable bacterium-like particle (BLP) obtained from a Gram-positive bacterium.

The invention claimed is: 
     
       1. An immunogenic composition in particulate form, comprising:
 i. a non-viable bacterium-like particle (BLP) obtained from a Gram-positive bacterium as particulate carrier; 
 ii. oligomers of a recombinantly produced polypeptide attached non-covalently to said BLP, wherein the recombinant polypeptide comprises:
 A) an N- or C-terminal antigenic domain, comprising at least one surface exposed polypeptide of pathogenic or tumour origin, or antigenic part thereof, the antigenic domain being fused to 
 B) an oligomerization domain (OMD), said oligomerization domain being fused via 
 C) a linker domain to 
 D) a peptidoglycan binding domain (PBD) consisting of a single copy of a LysM domain mediating the non-covalent attachment of the polypeptide to the BLP, and wherein the polypeptide as a whole contains only a single copy of a LysM domain; and 
 
 iii. a pharmaceutically acceptable diluent or excipient. 
 
     
     
       2. The immunogenic composition according to  claim 1 , wherein the surface exposed polypeptide in the antigenic domain of said recombinant polypeptide comprises an ectodomain of an enveloped virus protein. 
     
     
       3. The immunogenic composition according to  claim 2 , wherein said virus protein is from a virus selected from the group of viruses consisting of influenza virus, animal corona virus, human respiratory corona virus, human immunodeficiency virus (HIV), and parmixovirus. 
     
     
       4. The immunogenic composition according to  claim 2 , wherein said virus protein is from a virus is selected from the group of viruses consisting of syncytial virus (RSV) or metapneumovirus. 
     
     
       5. The immunogenic composition according to  claim 2 , wherein the surface exposed polypeptide or antigenic part thereof is selected from the group consisting of influenza hemagglutinin (HA) ectodomain or part thereof, influenza neuraminidase (NA) ectodomain or part thereof, coronavirus spike (S) protein ectodomain or part thereof, RSV glycoprotein F or G ectodomains or parts thereof and HIV gp140 ectodomain or part thereof. 
     
     
       6. The immunogenic composition according to  claim 1 , wherein said linker domain of said recombinant polypeptide consists of between 10 and 60, amino acids. 
     
     
       7. The immunogenic composition according to  claim 6 , wherein the linker domain comprises an amino acid sequence selected from the group consisting of: 
       
         
           
                 
                 
               
                     
                   (SEQ ID NO. 4) 
                 
                     
                   GASSAGNTNSGGSTTTITNNNSGTNSSST, 
                 
                     
                     
                 
                     
                   (SEQ ID NO. 5) 
                 
                     
                   GSASSTNSGGSNNSASTTPTTSVTPAKPTSQ, 
                 
                     
                   and 
                 
                     
                     
                 
                     
                   (SEQ ID NO. 6) 
                 
                     
                   QSAAASNPSTGSGSTATNNSNSTSSNSNAS. 
                 
             
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
       8. The immunogenic composition according to  claim 1 , wherein the oligomerization domain (OMD) of said recombinant polypeptide is a dimerization, trimerization or tetramerization domain. 
     
     
       9. The immunogenic composition according to  claim 1 , wherein the recombinant polypeptide furthermore comprises, in case of an N-terminal antigenic domain a C-terminal capping sequence, or in case of a C-terminal antigenic domain an N-terminal capping sequence. 
     
     
       10. The immunogenic composition according to  claim 1 , wherein said bacterium is a non-pathogenic bacterium. 
     
     
       11. The immunogenic composition according to  claim 1 , wherein the particulate carrier is provided non-covalently with at least a first oligomer of polypeptides comprising surface exposed polypeptides or antigenic parts thereof derived from a first pathogen and a second oligomer of polypeptides comprising surface exposed polypeptides or antigenic parts thereof derived from a second pathogen. 
     
     
       12. Method for providing an immunogenic composition  claim 1  comprising the steps of:
 a) providing a recombinant polypeptide as recited in  claim 1 , comprising culturing a host cell comprising an expression vector encoding said polypeptide in a suitable medium allowing for expression of the polypeptide, and isolating the polypeptide; 
 b) providing a non-viable bacterium-like particle (BLP) obtained from a Gram-positive bacterium, 
 c) allowing for non-covalent binding of said polypeptide(s) to said BLP to form an immunogenic complex comprising oligomers of a surface exposed polypeptide of pathogenic origin or antigenic part thereof bound non-covalently to a particulate carrier, and 
 d) formulating the immunogenic complex into an immunogenic composition. 
 
     
     
       13. A method for eliciting an immune response against a pathogen in an individual comprising administering to said individual an immunogenic composition according to  claim 1 . 
     
     
       14. Method according to  claim 13 , for eliciting an immune response against a viral disease in an individual, preferably wherein the viral disease is caused by influenza virus, animal coronavirus, human respiratory coronaviruses, human immunodeficiency virus (HIV), or paramyxovirus, in particular respiratory syncytial virus (RSV) or metapneumovirus. 
     
     
       15. The immunogenic composition according to  claim 1 , wherein said linker domain of said recombinant polypeptide consists of between 20 and 50 amino acids. 
     
     
       16. The immunogenic composition according to  claim 1 , wherein said linker domain of said recombinant polypeptide consists of between 25 and 40 amino acids. 
     
     
       17. The immunogenic composition according to  claim 1 , wherein said linker domain of said recombinant polypeptide consists of 30 amino acids. 
     
     
       18. The immunogenic composition according to  claim 1 , wherein the oligomerization domain (OMD) of said recombinant polypeptide is a GCN4 based dimerization, trimerization, or tetramerization domain; C-terminal domain sequence of T4, cipritin (foldon), or a functional part or analog thereof (C-terminal 27-30 residues); or the soluble trimerization domain of chicken cartilage matrix (CART) protein. 
     
     
       19. The immunogenic composition according to  claim 1 , wherein said bacterium is a food-grade bacterium. 
     
     
       20. The immunogenic composition according to  claim 1 , wherein said bacterium is selected from the group consisting of  Lactococcus , a  Lactobacillus , a  Bacillus  and a  Mycobacterium  ssp. 
     
     
       21. A recombinant polypeptide comprising:
 A) an N- or C-terminal antigenic domain, comprising at least one surface exposed polypeptide (e.g. of pathogenic or tumour cell origin) or antigenic part thereof, the antigenic domain being fused to 
 B) an oligomerization domain (OMD), said oligomerization domain being fused via 
 C) a linker domain to 
 D) a peptidoglycan binding domain (PBD) consisting of a single copy of a LysM domain capable of mediating the non-covalent attachment of the polypeptide to a peptidoglycan carrier particle being a non-viable bacterium-like particle (BLP) obtained from a Gram-positive bacterium, and wherein the polypeptide as a whole contains only a single copy of a LysM domain. 
 
     
     
       22. A nucleic acid sequence encoding a polypeptide according to  claim 21 . 
     
     
       23. A vector comprising a nucleic acid sequence according to  claim 22 . 
     
     
       24. A host cell, comprising a nucleic acid sequence according to  claim 22 , preferably wherein said host cell is a eukaryotic host cell, more preferably a mammalian host cell. 
     
     
       25. A host cell, comprising a vector according to  claim 23 .